The invention relates to a device and a method for foaming a liquid foodstuff, especially milk.
For foaming a liquid foodstuff, devices are known in which the liquid foodstuff, steam, and air are mixed in a foaming chamber, so that the liquid foodstuff is foamed and can be discharged by an outlet.
Especially for coffeemakers, it is known, for example, for preparing cappuccino, to foam milk with such devices. Typically, the air and/or milk is suctioned here by the Venturi effect due to the steam flow.
For example, in EP 00 243 326 A2, a device for foaming milk is described in which milk, steam, and air feed lines are connected to a foaming chamber. Milk and air are suctioned by the Venturi effect due to the steam flow. The device has hand-activated throttle valves for regulating the air flow and the milk flow.
Due to the great popularity of mixed coffee drinks, especially coffee-milk mixed drinks, devices for foaming liquid foodstuff are being used more and more. Especially in fine dining, high demands are placed on the quality of the foam being produced.
Furthermore, cold mixed drinks that contain foamed liquid foodstuff are also becoming more and more in demand. For producing cold milk foam, it is known from WO 2008/083941 A1 to feed milk by a pump to a throttle and then to selectively discharge directly via an outlet for producing cold milk foam or to first lead through a flow heater and then to discharge via an outlet for producing warm milk foam.
Also in the case of cold milk foam it is desired that this foam features a uniform fine porosity and thus stability. Due to the different desired foam types under different starting materials, such as, for example, milk at different temperatures or fat contents, as well as other liquid foodstuff with different viscosities, the production of the desired foam types has proven to be difficult.